Monopoly, to exist as an antithesis to competition, needs to be protected from the appearance of competition and that is most often accomplished by the state's interference which faciliatates the growth of monopolies by passing laws or assigning natural resources, patents and licences which allow a monopoly supply and production of unique goods. The state can also limit the growth of a monopoly or repress it completely. A monopoly, besides supplying and producing unique goods, characterizes itself with a lack of adequate substitutes and with a high monopoly price which is quite higher than the marginal cost which in the end results in a high profit. Monopolies usually have control over natural resources such as gas, water, electricity which allows them a lack of advertising because they possess essential resources which don't need any advertising and that gives them absolute power on the market, especially if it is about state monopoly or a state approved monopoly. There are real life examples of a state regulating monopolies in both ways.
The state with it's repression of a monopoly primarily helps consumers because the existence of a monopoly means that the consumer must pay a high price because there is no competition or adequate substitutes of the product or service he needs.